Belt conveyors comprise an endless belt that is formed from an elongated band of flexible material such as rubber or other suitable fabric. To form the endless belt, an elongated belt is folded upon itself in a loop and the two conveyor belt extremity sections are attached to each other to form the endless belt that can be carried in rotation about a set of rollers. Conveyor loop fasteners are typically used to attach both conveyor belt extremity sections to each other. These conveyor loop fasteners comprise a number of loops linked to a respective one of the two conveyor belt extremity sections, along the registering attachment edges thereof.
The loops of the conveyor loop fasteners are typically interlinked to form a continuous helical band, i.e. each loop represents one turn of the continuous helical band. Alternately, each loop of the conveyor loop fasteners could be a band of rings individually attached to the conveyor belt extremity section. In any event, the loops may be attached either directly onto the conveyor belt or to a short length of flexible sheet fabric that is in turn attached to the conveyor belt itself.
To attach the conveyor belt extremity sections to each other, the loops of both conveyor loop fasteners are fastened through interdigitation engagement. That is to say, each loop of the first conveyor loop fastener is inserted in-between two loops of the second conveyor loop fastener, and vice versa; with the exception, of course, of one loop at each extremity of the two attached conveyor loop fasteners which is the outermost loop and consequently adjacent to a single other loop. Once the loops are thusly fastened through interdigitation engagement, a wire or pintle is passed longitudinally along and within both conveyor loop fasteners and more particularly within the intersecting portions of the loops of both conveyor loop fasteners. When the pintle is in place, the conveyor loop fasteners are interlocked and cannot disengage unless the pintle is removed.
In some applications such as in the food and pharmaceutical industries, disassembling a conveyor is a daily business for cleaning purposes. Removing the pintle and reinserting a new one is tedious and time consuming. Indeed, the conveyor belt extremity sections are under considerable tension and significant friction exists when the pintle is forced through the intersecting conveyor loop fasteners. This friction is important enough that, in some cases, the heat generated by the friction will cause the plastic loops of the conveyor loop fasteners to melt.
Although it is possible to manually fasten the conveyor loop fasteners to each other, some fastening tools have been developed for this. Some of the tools however suffer from an important drawback: the tension between conveyor belt extremity sections needs to be reduced for the tools to be effective. This is often done by providing temporary attachments such as straps between the two conveyor belt extremity sections that allow the two conveyor belt extremity sections to be kept in close proximity while the conveyor loop fasteners are fastened. This method is disadvantageous in that it requires two attachment modes for the conveyor belt extremity sections: a first temporary attachment mode to reduce the tension in the conveyor belt and a second attachment mode can only be accomplished after the first attachment has been done.
The loops of some conveyor loop fasteners have a constant cross-section. Alternately, to increase the strength of the interlocking engagement between the conveyor loop fasteners, it is known to provide each fastening loop with a flat head portion located opposite its attachment to the conveyor belt extremity section to which it is attached. This may be done for example by heat-stamping the conveyor loop fastener to form this flattened head section.
The fastening of the two conveyor loop fasteners that have flattened loop head portions can be accomplished by arching each conveyor loop fastener so as to spread the loops of each conveyor loop fastener apart. The conveyor loop fasteners, usually forming a helical band, are usually semi-flexible, e.g. made of resilient plastic, to allow this yielding deformation to occur.